wip

By doing something like
```
fn input_output_loop(input_output: Subject(List(String))) -> Nil {
  let output = process.receive_forever(input_output)

  echo output

  input_output_loop(input_output)
}
```

src/input/key.gleam

@@ -62,7 +62,7 @@ pub fn start_raw_shell() {
 
 pub fn read_input_until_key(
   l: List(String),
-  tap_input: Subject(List(String)),
+  input_sink: Subject(List(String)),
 ) -> Key {
   case
     internal_input.read_input()
@@ -71,9 +71,13 @@ pub fn read_input_until_key(
     |> from_list
   {
     Continue(l) -> {
-      process.send(tap_input, l)
-      read_input_until_key(l, tap_input)
+      echo "key:read_input_until_key continue: " <> string.inspect(l)
+      process.send(input_sink, l)
+      read_input_until_key(l, input_sink)
+    }
+    k -> {
+      echo "key:read_input_until_key k: " <> string.inspect(k)
+      k
     }
-    k -> k
   }
 }

src/mpv/control.gleam

@@ -10,6 +10,8 @@ import tcp/tcp.{type Socket}
 pub type Control {
   TogglePlayPause
 
+  Search
+
   Exit
 }
 
@@ -27,6 +29,7 @@ pub fn from_key(key: Key) -> Result(Control, Nil) {
 fn char_control(char: String) -> Result(Control, Nil) {
   case char {
     " " -> Ok(TogglePlayPause)
+    "/" -> Ok(Search)
     "q" -> Ok(Exit)
     _ -> Error(Nil)
   }

src/mpv/mpv.gleam

@@ -8,17 +8,22 @@ import input/key.{type Key}
 import mpv/control.{type Control}
 import tcp/reason
 import tcp/tcp.{type Socket}
+import ui/ui.{type Event}
 
-type State(socket, inject_input, tap_input, exit) {
+type State(socket, inject_input, ui, exit) {
   State(
     socket: Socket,
     inject_input: Subject(Key),
-    tap_input: Subject(List(String)),
+    ui: Subject(Event),
     exit: Subject(Nil),
   )
 }
 
-pub fn new(exit: Subject(Nil)) -> Result(Nil, String) {
+pub fn new(
+  ui: Subject(Event),
+  input_sink: Subject(List(String)),
+  exit: Subject(Nil),
+) -> Result(Nil, String) {
   // TODO start up mvp here, currently hi-jacking `naviterm`s socket
   let socket_path = "/tmp/naviterm_mpv"
 
@@ -31,11 +36,8 @@ pub fn new(exit: Subject(Nil)) -> Result(Nil, String) {
       let inject_input_name = process.new_name("inject_input")
       let inject_input = process.named_subject(inject_input_name)
 
-      let tap_input_name = process.new_name("tap_input")
-      let tap_input = process.named_subject(tap_input_name)
-
       case
-        actor.new(State(socket, inject_input, tap_input, exit))
+        actor.new(State(socket, inject_input, ui, exit))
         |> actor.on_message(handle_message)
         |> actor.start
       {
@@ -49,7 +51,7 @@ pub fn new(exit: Subject(Nil)) -> Result(Nil, String) {
             let assert Ok(_) =
               process.register(process.self(), inject_input_name)
 
-            read_input(data, inject_input, tap_input)
+            read_input(data, inject_input, input_sink)
           })
 
           Ok(Nil)
@@ -60,10 +62,16 @@ pub fn new(exit: Subject(Nil)) -> Result(Nil, String) {
 }
 
 fn handle_message(
-  state: State(socket, inject, input_output, exit),
+  state: State(socket, inject, ui, exit),
   control: Control,
-) -> actor.Next(State(socket, inject, input_output, exit), Control) {
+) -> actor.Next(State(socket, inject, ui, exit), Control) {
   case control {
+    control.Search -> {
+      echo "mpv search"
+      process.send(state.inject_input, key.Continue([key.input_introducer]))
+      process.send(state.ui, ui.Search)
+      actor.continue(state)
+    }
     control.TogglePlayPause -> {
       echo "toggling play/pause"
 
@@ -94,7 +102,7 @@ fn handle_message(
 fn read_input(
   subject: Subject(Control),
   inject_input: Subject(Key),
-  tap_input: Subject(List(String)),
+  input_sink: Subject(List(String)),
 ) -> Nil {
   let buffer = case process.receive(inject_input, 1) {
     Ok(key.Continue(buffer)) -> buffer
@@ -102,9 +110,9 @@ fn read_input(
   }
 
   let _ =
-    key.read_input_until_key(buffer, tap_input)
+    key.read_input_until_key(buffer, input_sink)
     |> control.from_key
     |> result.map(process.send(subject, _))
 
-  read_input(subject, inject_input, tap_input)
+  read_input(subject, inject_input, input_sink)
 }

src/musicplayer.gleam

@@ -1,8 +1,30 @@
 import gleam/erlang/process
+
 import mpv/mpv
+import ui/ui
 
 pub fn main() -> Nil {
+  // 1. user starts search
+  // ui should show "input: "
+  // user presses enter
+  // ui should show "input was: x"
+
+  // 1. listen for control.Search
+  // 2. start listening to tap_input and print io.print "input: "
+  // 3. simultaniously listen for control.Input
+  // 4. print "input was: x"
+
+  // ui need: tap_input
+  // input need: ui subject to send control events from
+
+  // new input process should return `Key`
+  // this key should be sent both to ui and mpv, and they will decide if they can act on it.
+  // its probably ok if both act on it, e.g. "TogglePlayPause" could stop mpv music and display |> or || in ui
+
   let exit = process.new_subject()
-  let assert Ok(_) = mpv.new(exit)
+
+  let assert Ok(#(ui, input_sink)) = ui.new()
+  let assert Ok(_) = mpv.new(ui, input_sink, exit)
+
   process.receive_forever(exit)
 }

src/ui/ui.gleam

@@ -0,0 +1,62 @@
+import gleam/erlang/process.{type Name, type Subject}
+import gleam/otp/actor
+import gleam/string
+
+pub type Event {
+  Search
+  Input(List(String))
+}
+
+// TODO in input, split input into events and control?
+
+pub fn new() -> Result(#(Subject(Event), Subject(List(String))), String) {
+  let input_sink_name: Name(List(String)) = process.new_name("input_sink")
+  let input_sink = process.named_subject(input_sink_name)
+
+  // let input_sink = process.new_subject()
+
+  case
+    actor.new(Nil)
+    |> actor.on_message(handle_message)
+    |> actor.start
+  {
+    Error(start_error) ->
+      Error("Could not start ui actor: " <> string.inspect(start_error))
+    Ok(actor.Started(data: ui, ..)) -> {
+      echo "ui started"
+
+      // let assert Ok(_) = process.register(process.self(), input_sink_name)
+      process.spawn(fn() {
+        let assert Ok(_) = process.register(process.self(), input_sink_name)
+        drain_input_sink(ui, input_sink)
+      })
+
+      Ok(#(ui, input_sink))
+    }
+  }
+}
+
+fn handle_message(state: Nil, event: Event) -> actor.Next(Nil, Event) {
+  case event {
+    Search -> {
+      echo "ui:search"
+      actor.continue(state)
+    }
+    Input(content) -> {
+      echo "ui:input: " <> string.inspect(content)
+      actor.continue(state)
+    }
+  }
+}
+
+fn drain_input_sink(
+  subject: Subject(Event),
+  input_sink: Subject(List(String)),
+) -> Nil {
+  echo "ui:drain_input_sink"
+  let content = process.receive_forever(input_sink)
+
+  process.send(subject, Input(content))
+
+  drain_input_sink(subject, input_sink)
+}